Piston ring



April 1, 1952 F, M O 2,591,176

PISTON RING Filed Dec. 1, 1949 I151... IE1E E 1113 E 11.52%. 5) J72 J3J5 5 5 15 2 J] .ZZ g JJ 6 2 20 g Patented Apr. 1, 1952 UNITED STATESPATENT OFFICE The present invention relates to improvements in packingand sealing elements, and more particularly to a piston ring for sealingthe pistons of motors, pumps and internal combustion enines.

One object of the invention is to provide a piston ring of the splittype with a metal plate adapted to close the gap in the split ring sothat the ring will be expanded radially outward by gases or fluids whichpass behind the ring between the radial groove wall of the piston ringin the piston.

Another object is to provide a split piston ring having a gap closingplate to provide a sealing wall for the ring and prevent the escape ofgases and fluids through the gap so that the expansion forces of saidfluids and gases will be exerted on the piston ring in a directionradially outward.

Another object is to provide a split piston ring having mutuallyengaging stepped surfaces forming the gap of said split ring with aplate-like backing member secured to one end of the ring and arranged tobe brought into engagement with the opposite end of the ring.

Another object is to provide a split piston ring with a gap formed bymutually engaging stepped surfaces in which a sealing plate is mountedin back of said stepped surfaces to partially close the mutually steppedportions of the gap in all positions of expansion and contraction.

Another object is to provide a split piston ring having a sealing platemounted in back of the gap with one end of the ring free to moverelative to the plate. The sealing plate being aflixed to one end of thering by welding or the like and arranged in sliding contactualengagement with the other end of the split ring.

Other objects and advantages of the invention will become apparentduring the course of the following description of the accompanyingdrawing wherein:

Figure 1 is a top elevational view of a piston ring showing the mannerin which the sealing plate is mounted in the back of the split ring ap.

the sealing plate will effectively seal the gap such that compressiveforces in the piston groove will urge the piston ring into tight sealingengagement with the walls of the cylinder. Figure 4 is a rearelevational view and cross section taken on line 4-4 of Figure 1 andlooking in the direction of the arrows to further illustrate the shapeand location of the gap sealing plate.

Figure 5 is an enlarged fragmentarytop elevational view showing thesealing plate aflixed to the left hand end on the left side of the gapand extending over the mutually engaging stepped surfaces in slidingengagement with the right hand or side of the gap.

Figure 6 is an enlarged fragmentary bottom plan view showing the sealingplate aflixed to the right hand side of the gap and freely movable withthe other end of the gap.

Figure 7 is an enlarged fragmentary front "elevational view of the splitpiston ring gap showing the manner in which the sealing plateeffectively closes the openings when the ring is compressed, and

Figure 8 is a vertical cross-sectional view taken on line 8--8 of Figure7 and looking in the direction of the arrows to show the manner in whichthe sealing ring is constructed and the position of the sealing plate.

In the drawing, and more in detail, there is shown for the purpose ofconvenience of illustration a piston ring generally designated 5comprising a circular body 6 of substantially square section, and saidring 5 is split as at I to permit expansion and contraction to enablethe ring to be assembled in the groove of a piston (not shown) and theninserted in a cylinder by com- Figure 2 is a bottom elevational viewfurther pressing the ring to the circular size of the cylinder. Thepiston ring end portions 9 and ID are provided with mutually engagingsurfaces and as noted in the drawing the end 9 is cut vertically as at Hto provide a stepped surface It terminating in a vertical end wallportion J3.

The invention comprises a sealing plate 20 which is mounted on the innercircumferential surface of the piston ring 6 and is secured as bywelding or the like to the end 9 adjacent the gap 1. The plate 20 isslightly arcuate to conform to the circular shape of the innerperipheral Wall of the piston ring 6 and is arranged to terminate at thepoint of the surface l3 so that when said ends 5 and H] are movedtogether by compressing the ring 6, the sealing plate 20 will engage theinner peripheral edge'surface of the end II].

The sealing plate 20 is rectangular in shape and as illustrated in thedrawing, is of suflicient. length to completely close and seal thelower" portion of said gap 1 against the passage-of gases during thecompression or expansion strokes of the pump or engine on which the ringis used. Further, it is noted that the sealing plate 2!} is formed ofvery thin metal stock such that the overall. thicknessof the/sealingplate and ring will not equal the depth of thepiston ring groove of aninternal combustion engine or pump piston.

The sealing-plate 20 is preferably held in place by beingsspotwelded tothe end 9 of the split ring 6-, but it'is obvious. that it can beaifixed thereto in various ways.- However, spot welding is the mosteconomical, and since piston rings are a production article it has beenfound that welding the plate. 20' inposition saves considerable-time anddoes not add materially to the cost of the piston; ring. 7

In operation, the piston ring 5- is installed in the sealing groove of,a pump or internal combustion engine piston such thatthering. is undercompression when in its operative position in the cylinder ofuan:engine. or pump with the gap 1 "closed as shown in Figures 5 to 8inclusive. In

this position, the sealing plate 20 partially closes the gap between thestepped surfaces I |-l'6- and In other words, gas under pressureentering the ring groove through the gap 2|, upon compression andpower'strokes, cannot. escape through the lower sealed gap 22. andtravel on past the piston. Consequently, this gas under pressure willact radially against the ring 5' and hold it against the cylinder wall.

From the 'above description when taken in connection wtih' theaccompanying drawing, it: will be seen that there has been provided ameans whereby the ring is radially urged into tight contactualengagement with the walls of the cylinder without relying upon theusual. type of expansion elements. The plate 2|] can be very cheaplymanufactured and its attachmentto the 4 1 ring represents a very simpleoperationrand will not materially add to the cost of the piston ring.

I claim:

1. In a packing element for the pistons of internal combustion enginesand pumps, a split ring having a scarfed joint and a sealing plateafiixed to one end of said ring and terminating flush with the endthereof to close the lower portion of said joint.

2. In a piston packing element for internal combustion engines, asplitring having. a scarfed joint and an arcuately curved sealing platesecured to the inner periphery of said ring and arranged to terminateflush with one end of said ring to close the lower portion of said gapat said joint;

3. In a piston packing element for internal combustion engines andpumps, a split ring having. a joint provided with stepped mutuallyopposed surfaces, a sealing plate aflixed to the inner peripheralsurface of the. ring adjacent the joint and projecting beyond thestepped portion at one end of said ring to overlie a portionv of theother end of saidv ring. and provide a restricted opening for theingress of expansion gases.

4. In a piston. packing. element for internal combustion engines andpumps, a split ring. having a joint provided with. stepped mutuallyopposed surfaces, aniarcuately curved sealing. plate affixed tothe-inner peripheral surface of the ring adjacent oneend to bridgesaidjoint andslid'ably engage the end of said ring opposite said plate saidplate being arranged to close the space between the lower steppedmutually engaging surfaces while leaving the space between-'the upperstepped surfaces open.

5-. In a piston packing element for internal combustion engines andpumps, a split ring having a joint formed by stepped mutually opposedsurfaces, an arcuately curved sealing plate: welded to the inner peripheralsurfaceof the; ring ad'- jacent thev jointarranged to bridge. the'sameand slidably engage the inner surface of the other end of the ring, saidplate being arranged to close the space between the lower steppedmutually engaging surfaces; while leaving the spacebetween. the upperstepped surfaces open.

ROBERT F. MASON.

REFERENCES CITED The following references are of record in the file ofthis patent:

' UNITED STATES PATENTS

